Changes in the physiology of the cotton plant could make future fiber easier to clean in the ginning process, says Rick Byler, research leader at the USDA Cotton Ginning Laboratory at Stoneville, Miss.

“One of the issues we’re interested in is the effect of variety on ginning,” he said at the annual meeting of the Southern Cotton Ginners Association, held in conjunction with the Mid-South Farm and Gin Show at Memphis.

“It’s something we’ve known about for a long time, but we don’t feel it’s been studied well enough. “Cliff Boykin, research engineer, has been working on this with some of the geneticists at Stoneville, the University of Arkanasas, and Mississippi State University.
“For example, cotton plants have hairs — different cultivars have different amounts, most notably on the leaves, some on the bracts — and these hairs have an impact on cleaning in the ginning process.

“The hairs on the leaves are useful to help keep insects off the plant,” Byler says, “One of the concepts they’re looking at is to perhaps develop varieties that retain hairs on the leaves, but remove them from the bracts to make the cleaning process more efficient.”

Another example is the impact that variety has on energy requirements for ginning, he says.

“Bill Meredith, USDA cotton geneticist at Stoneville, has observed that in some varieties the fiber is attached more tightly to the seed, while in others it separates very easily. We’re doing tests in the lab to determine how much energy it takes to pull fiber off the seed and how that relates to variety.”

These projects have been partially supported by Cotton Incorporated.

Work is also in progress, Byler says, on a gin dust study,

supported by each of the regional ginner groups, Cotton Incorporated, and state and federal funding.

The Environmental Protection Agency sets standards for limits of fine dust (PM2.5), based on how much dust it takes to cause health problems, he notes.

“State regulatory agencies then had to estimate gin emissions of fine dust, which are higher than some previous ginning research suggests. Most dust from a cotton gin is large dust that doesn’t affect health.

“The problem is the lack of fine dust data associated with sampling agricultural dust, such as from gins — which is quite different from urban dust.

“We wanted to include the entire cotton belt in this study, and all the ginning labs are working on it. We’re getting close to being ready to analyze the data and come up with some numbers.”

Bobby Hardin, an engineer at the ginning lab, has been measuring energy use by gins in a project also supported by Cotton Incorporated, Byler says.

“Data we’ve accumulated thus far should encourage you to keep your gin stands loaded. For an individual gin, as bales ginned per hour increases, the amount of electricity used per bale decreases. Keeping your gin stands fully loaded will allow the most efficient use of your electricity.”

And, Byler says, the time required to deal with a gin breakdown can also have an impact on energy use and labor costs.

“If your breakdown is short, less than 12 minutes, you should go ahead and let the gin continue running. But if it’s going to take more than 12 minutes to correct the problem, you should shut the gin down, then restart it when the repair is done.”

Ginners should also work with their producers to try and have cotton at a proper moisture content for ginning, Byler says.

“When cotton is a bit wet, it slows the gin. Work with your producers to protect the cotton so it can enter the gin at the proper moisture level to insure optimum efficiency of ginning and fuel use.”

In another project, Byler says, a study was conducted at a commercial gin where they were reclaiming usable lint rejected by seed cotton cleaners.

“They averaged about 19 pounds of reclaimed material per bale. About 36 percent was loose lint, 37 percent was motes, and 12 percent was partially-ginned seed cotton by weight.

“This is a fair amount of weight being lost per bale,” Byler says. “When we looked at quality, this material was shorter and had more neps, but it was still of fairly good quality. When mixed in with other fiber before the lint cleaners, there was no detectable difference in HVI readings. We don’t have spinning data yet – which will be the ultimate test as to whether there is a quality difference.”